She said that voters, while secretive about their favoured candidates, were blunt about wanting more food, money, and job security.

'Important day'

"[Sunday] is an important day for the country's future," Rene Preval, the outgoing president, said on Saturday in a recorded broadcast message, urging voters to act with "order and discipline ... so election day goes off well and Haiti can move forward".

More than 4.7 million people are eligible to vote. Results are to be made public from December 5, with the official tally announced on December 20.

The new president will lead the poorest country in the western hemisphere, a nation of around 10 million people where 80 per cent of the population lives on less than two dollars a day.

Front-runners among the 18 candidates include Jude Celestin, an engineer supported by Preval; academic and former first lady Mirlande Manigat; and Michel Martelly, a popular singer widely known as "Sweet Micky".

Some opinion polls put Manigat, whose husband was helped to power and then deposed by a military junta, as a more popular contender than Celestin.

Martelly, known for his Kompa dance music, has had thousands of urban youths toting his pink signs and shouting to "Vote for the bald head!''

Multiple crises

The election comes as Haiti battles a cholera outbreak that has claimed at least 1,648 lives. It is also the first election since a devastating 7.0-magnitude earthquake in January killed more than 250,000 people.

Al Jazeera's Sebastian Walker, reporting from the capital, Port-au-Prince, said that it has been difficult for internally displaced Haitians to get to the polls.

Our correspondent said makeshift booths have been set up in the tent cities to facilitate voting.

Clashes among rival political camps caused several deaths in recent weeks. At least one person was killed in a clash between Celestin's and Baker's supporters in the far western town of Jeremie.

On Friday night, Martelly aides said a hail of bullets ended his campaign-closing rally in the southwestern peninsula town of Les Cayes, with one supporter reported killed.

His campaign blamed the unconfirmed attack on "Mr Preval and his heir-apparent, Mr Jude Celestin, (and) the Unity (party) hierarchy.''